NSN 7R-1680-016247029-YR, REF NR 449-005-231-123, QTY 9 EA, DELIVERY FOB ORIGIN. This part requires engineering source approval by the design control activity in order to maintain the quality of the part. Existing unique design capability, engineering skills, and manufacturing knowledge by the qualified source(s) require acquisition of the part from the approved source(s). The approved source(s) retain data rights, manufacturing knowledge, or technical data that are not economically available to the Government, and the data or knowledge is essential to maintaining the quality of the part. An alternate source must qualify in accordance with the design control activity's procedures, as approved by the cognizant Government engineering activity. The qualification procedures must be approved by the Government engineering activity having jurisdiction over the part in the intended application.